Liquid polysulfide polymers have thiol groups at the terminals, and thus are easily oxidized and cured by an oxidizing agent such as lead dioxide and manganese dioxide. Rubber-like cured products obtained by curing polysulfide polymers contain sulfur in the main chain of the molecule, and do not contain double bonds, and thus have excellent features in oil resistance, weather resistance, water tightness and air tightness, and also have fine adhesibility, and thus are widely used as sealants, adhesives and paints.
The most common method of producing a polysulfide polymer is a method of obtaining a liquid polymer through a solid polysulfide described in U.S. Pat. No. 2,466,963. Furthermore, a production method using a phase transfer catalyst has been reported (see U.S. Pat. No. 6,939,941).
The thioether described in WO 2009/131796 is a thioether that does not substantially contain polysulfide bonds, and the reference describes that the thioether is formed into a sealant that is excellent in fuel resistance and the like.
The polythioether polymer described in WO 1998/039365 is a polythioether that does not contain polysulfide bonds and shows excellent low temperature flexibility and fuel oil resistance when it is cured, and thus is used as a sealant as in conventional polysulfide polymers.
A sealant composition that utilizes both of the properties of a polysulfide polymer and a polythioether polymer by blending these polymers is known (see WO 2006/029144).
Conventional polysulfide polymers are excellent in oil resistance, weather resistance, stabilities at low temperatures and high temperatures, and the like, and thus are used in various sealants and adhesives. In addition to those properties, especially in sealants for aircraft, further heat resistance, cold resistance and low specific gravity are required. Furthermore, lowering of viscosity is also desired to decrease solvents in sealants. On the other hand, in construction sealants, excellent weather resistance is required, and elastic recovery for following the motion of a joint is required in the case of application for a sealant on movable part.